A highactivity ATP translocator in mesophyll chloroplasts of Digitaria sanguinalis, a plant having the C-4 dicarboxylic acid pathway of photosynthesis

The effect of exogenous adenine nucleotides on CO2 fixation and oxygen evolution was studied with mesophyll protoplast extracts of the C4 plant Digitaria sanguinalis. Exogenous ATP was found to stimulate the rate of pyruvate and pyruvate+oxalacetate induced CO2 fixation, as well as reverse the inhibition of CO2 fixation of carbonyl cyanide m-chlorophenyl hydrazone and several electron transport inhibitors. The ATP-dependent stimulation of CO2 fixation varied from 40 to 70 mumol CO2 fixed/mg chlorophyll per h, suggesting that ATP was crossing the chloroplast membranes at rates of 80-140 mumol/mg chlorophyll per h, since 2 ATP are required for each CO2 fixed. Fixation of CO2 could also be induced in the dark by exogenous ATP, in which case ADP accumulated outside the chloroplasts...     

Determination of background serum density for lipoprotein ultracentrifugation

It is necessary to know the density of serum exclusive of its macromolecules (background density) prior to density adjustment with solid potassium bromide for ultra-centrifugal separation of lipoprotein fractions. To evaluate this, we compared the densities of the corresponding ultrafiltrates or dialysates of both human and equine sera produced by ultrafiltration and equilibrium dialysis method for macromolecule removal. Excellent correlation is found between background densities determined following ultrafiltration or equilibrium dialysis. These data validate the use of ultrafiltration as a simple, direct method for determination of background serum densities but reveal equilibrium dialysis to be more time consuming and less precise. Using ultrafiltration, we find the background density for equine serum to be 1.004 g/ml, and initial investigation suggests this value may be altered by freezing, prolonged refrigeration (3 months), or heating to inactivate lecithin: cholesterol acyltransferase.     

Does age of the host affect growth rates of skeletal malignancies?

Statistical analysis of bone tumor growth rates as a function of age at initiation of radiation-induced skeletal malignancies in our animal colony indicated that the p value for an association between these parameters was <0.05, suggesting a correlation in beagle dogs. The youngest animals appeared to exhibit the most slowly growing tumors, and the trend was toward more rapidly growing tumors with increasing age. Less effective immune systems in older animals were invoked as a possible explanation of this relationship.     

NSAIDS inhibit the IL-1 beta-induced IL-6 release from human post-mortem astrocytes: the involvement of prostaglandin E2

Epidemiological studies have shown that steroidal as well as non-steroidal anti-inflammatory drugs lower the risk of developing Alzheimer's Disease (AD). A suppressive effect of these anti-inflammatory drugs on local inflammatory events in AD brains has been suggested, however the mechanisms responsible are still unknown. In this study we investigated at cellular level the influence of two anti-inflammatory drugs-dexamethasone and indomethacin--and an experimental specific cyclooxygenase-2 inhibitor, BF389, on the production of the pro-inflammatory cytokine IL-6 and the inflammatory mediator PGE2 by human astrocytes. Two human post-mortem astrocyte cultures (A157 and A295) and astroglioma cell lines (U251 and U373 MG) were found to secrete considerable amounts of IL-6 upon stimulation with IL-1beta. The glucocorticoid dexamethasone inhibited the IL-1beta-activated release of IL-6 from the postmortem astrocyte cultures A157 and A295 and from the astroglioma cell lines. The non-specific cyclooxygenase inhibitor indomethacin and BF389 only suppressed the IL-6 release by post-mortem astrocyte culture A157. This post-mortem astrocyte culture was found to produce large amounts of PGE2 upon stimulation with IL-1beta, whereas in the supernatants of the postmortem astrocyte culture A295 and the astroglioma cell lines, low PGE2 concentrations were detected. Addition of exogenous PGE2 prevented the inhibitory effect of indomethacin and BF389 on the IL-1beta-activated IL-6 release from A157 astrocytes and largely potentiated the IL-1-induced release of IL-6 from all astrocytes/astroglioma cells tested. Dexamethasone also inhibited the PGE2 release from the astrocytes and astroglioma cells, however the inhibitory effect of dexamethasone on the IL-1beta-activated IL-6 release could not be prevented by the addition of PGE2. The observed reduction of IL-6 and/or PGE2 from astrocytes may be involved in the mechanism underlying the beneficial effects of these drugs in AD.     

Meeting the bereavement needs of kids in patient/families--not just playing around

Children grieve differently than adults. Although the unit of care in hospice is the patient and family, emphasis is often on the grown members of the family and the anticipatory grief and bereavement needs of children and adolescents are sometimes not met adequately. In this paper, hands-on strategies for working with children both before and after a significant death are presented, as well as appropriate context information on the grieving process for youth under age 18.     

Quinine for leg cramp: time to call a halt?

The MURCS association is traditionally regarded as a disorder limited to the female sex. It has been hypothesized that men displaying the combination of azoospermia, segmentation abnormalities of the cervicothoracic spine and renal anomalies may have a male analogue of MURCS. Here we describe a patient with non-obstructive azoospermia and Klippel-Feil anomaly type II and suggest that this may represent another case of 'MURCS in the male'.